A Brief History of US Interventionism in Iran and Beyond // Trending Globally

Brown Watson Institute
Brown Watson InstituteMar 24, 2026

Why It Matters

Understanding the historic expansionist mindset clarifies why the United States continues to intervene abroad, shaping policy risks and global perceptions.

Key Takeaways

  • Manifest Destiny drove U.S. expansion beyond continental borders.
  • 1890 census declared frontier closed, prompting new ambitions.
  • Two paths: model nation or continued territorial conquest.
  • Expansionist impulse rooted in early settlers’ restless mindset.
  • Power enables actions, even when self‑defeating or controversial.

Summary

The video traces the evolution of American interventionism from 19th‑century Manifest Destiny to modern overseas actions, using the 1890 Census declaration that the continental frontier was closed as a turning point.

It argues that once domestic expansion ended, the United States faced a choice: become a model society for the world or pursue further territorial and political domination. The speaker emphasizes that the expansionist drive was embedded in the psyche of early settlers who constantly sought new lands to conquer.

A striking quote underscores this mindset: “who came to America… wanted to go to a new place that they didn’t know about and overrun it and make it theirs.” The narrator also notes the rarity of a nation possessing the power to intervene yet deciding to act, even when such actions may be self‑defeating.

The implication is that contemporary U.S. interventions, such as in Iran, are rooted in this historic impulse, suggesting that strategic overreach remains a structural risk for American foreign policy.

Original Description

Stephen Kinzer, a Senior Fellow at Brown University’s Watson School of International and Public Affairs, and author of “All the Shah’s Men: An American Coup and the Roots of Middle East Terror,” discusses the history of US foreign intervention on the Watson School’s podcast, Trending Globally.
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